Ah, I didn't realise that it was 'a thing' - I thought that they had made it up!
I never bothered with Stobarts, but my dad and I always used to do Norbert spotting on our trips to France & Belgium.
There was a Turkish (I think) transport company with red lorries and a logo that could be mistaken for a Norbert from a distance. Always a risk when calling a Norbert early that it might be one of those instead. Lose a point for a wrong call.